Image capturing apparatus and control method thereof, and storage medium

Abstract

An image capturing apparatus includes: an image sensor; a readout unit capable of switching between carrying out a first readout operation of reading out signals from photoelectric conversion elements corresponding to a first number of pupil areas and a signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas, and a second readout operation of reading out signals from photoelectric conversion elements corresponding to a second number and a signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas; and a control unit that controls whether to cause the readout unit to carry out the first readout operation or the second readout operation in accordance with a status of the image capturing apparatus.

What is claimed is: 
     
       1. An image capturing apparatus comprising:
 an image sensor in which pixels are arrayed two-dimensionally, each of the pixels including a plurality of photoelectric conversion elements for a single microlens; 
 a readout unit capable of switching between carrying out a first readout operation of reading out, from the image sensor and at a first framerate, signals from photoelectric conversion elements corresponding to a first number of pupil areas among a plurality of pupil areas of an imaging optical system and a signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas among the plurality of pupil areas of the imaging optical system, and a second readout operation of reading out, from the image sensor and at a second framerate, signals from photoelectric conversion elements corresponding to a second number, different from the first number, of pupil areas among the plurality of pupil areas of the imaging optical system and a signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas among the plurality of pupil areas of the imaging optical system; and 
 a control unit that controls whether to cause the readout unit to carry out the first readout operation or the second readout operation in accordance with a status of the image capturing apparatus. 
 
     
     
       2. The image capturing apparatus according to  claim 1 ,
 wherein the signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas among the plurality of pupil areas of the imaging optical system is a signal obtained by adding together all of the signals from the plurality of photoelectric conversion elements corresponding to the single microlens for each of the pixels in the image sensor. 
 
     
     
       3. The image capturing apparatus according to  claim 1 ,
 wherein the signals from the photoelectric conversion elements corresponding to the first number of pupil areas and the signals from the photoelectric conversion elements corresponding to the second number of pupil areas are signals obtained by dividing the plurality of photoelectric conversion elements in each of the pixels into a plurality of groups and then adding the signals from the photoelectric conversion elements in each of the plurality of groups. 
 
     
     
       4. The image capturing apparatus according to  claim 3 ,
 wherein the control unit changes the grouping method for dividing the plurality of photoelectric conversion elements into the plurality of groups in the second readout operation on the basis of the signals from the photoelectric conversion elements corresponding to the first number of pupil areas read out in the first readout operation. 
 
     
     
       5. The image capturing apparatus according to  claim 1 ,
 wherein the control unit causes the readout unit to carry out the first readout operation in the case where the image capturing apparatus carries out a live view operation and does not carry out lens driving for focus adjustment, and the control unit causes the readout unit to carry out the second readout operation in the case where the image capturing apparatus carries out the live view operation and carries out the lens driving for focus adjustment. 
 
     
     
       6. The image capturing apparatus according to  claim 5 ,
 wherein the second framerate is a higher framerate than the first framerate. 
 
     
     
       7. The image capturing apparatus according to  claim 1 , further comprising:
 a detection unit that detects an image shift amount from the signals from the photoelectric conversion element corresponding to the first number of pupil areas and the signals from the photoelectric conversion elements corresponding to the second number of pupil areas. 
 
     
     
       8. The image capturing apparatus according to  claim 7 , further comprising:
 a calculation unit that calculates a lens driving amount using the image shift amount. 
 
     
     
       9. A method of controlling an image capturing apparatus including an image sensor in which pixels are arrayed two-dimensionally, each of the pixels including a plurality of photoelectric conversion elements for a single microlens, the method comprising:
 switching between carrying out a first readout operation of reading out, from the image sensor and at a first framerate, signals from photoelectric conversion elements corresponding to a first number of pupil areas among a plurality of pupil areas of an imaging optical system and a signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas among the plurality of pupil areas of the imaging optical system, and a second readout operation of reading out, from the image sensor and at a second framerate, signals from photoelectric conversion elements corresponding to a second number, different from the first number, of pupil areas among the plurality of pupil areas of the imaging optical system and a signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas among the plurality of pupil areas of the imaging optical system; and 
 controlling whether to cause the first readout operation or the second readout operation to be carried out in accordance with a status of the image capturing apparatus. 
 
     
     
       10. A non-transitory computer-readable storage medium storing a program for causing a computer to execute the steps of a method of controlling an image capturing apparatus including an image sensor in which pixels are arrayed two-dimensionally, each of the pixels including a plurality of photoelectric conversion elements for a single microlens, the method comprising:
 switching between carrying out a first readout operation of reading out, from the image sensor and at a first framerate, signals from photoelectric conversion elements corresponding to a first number of pupil areas among a plurality of pupil areas of an imaging optical system and a signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas among the plurality of pupil areas of the imaging optical system, and a second readout operation of reading out, from the image sensor and at a second framerate, signals from photoelectric conversion elements corresponding to a second number, different from the first number, of pupil areas among the plurality of pupil areas of the imaging optical system and a signal obtained by adding together signals from the photoelectric conversion elements corresponding to all of the pupil areas among the plurality of pupil areas of the imaging optical system; and 
 controlling whether to cause the first readout operation or the second readout operation to be carried out in accordance with a status of the image capturing apparatus.